BT chairman Sir Mike Rake said yesterday that a vote to remain in the European Union would enable the UK to help shape further reform.

He was speaking to the media following a private “town hall” meeting attended by around 400 BT staff at its Adastral Park research centre near Ipswich, where BT employs a total of around 3,000 people.

The meeting came a day after Sir Mike, BT chief executive Gavin Patterson and senior figures from the CWU and Progress unions wrote a joint letter to BT’s 80,000 employees backing a “remain” vote in next week’s referendum.

Sir Mike said that “only one or two” questions yesterday had related to Europe, with most focusing on the company’s future after its acquisition of mobile operator EE and the current regulatory environment.

He said that, like the letter, he had made it clear that it was up to each individual to decide for themselves how to vote but BT, like the CBI and a majority of businesses, believed the net benefit lay firmly on the side of Britain staying in the EU.

Sir Mike said he believed that Prime Minister David Cameron had been successful in his renegotiation efforts ahead of the referendum campaign, and that further reform was possible if Britain stayed and engaged in the process.

“Some EU reforms have taken too long but we also have work to do ourselves, in terms of our fiscal deficit and productivity,” he said. “Our fiscal deficit is the biggest in the EU except for Greece and in productivity we are behind countries such as France and Germany.”

Sir Mike said he was confident that BT would be able to retain ownership of its Openreach fixed line network business, the performance of which has come under scrutiny from industry regular Ofcom amid complaints from some of BT’s rivals who have called for it to be split-off.

He said that, in 2009, BT had gone ahead with a major roll-out of fibre broadband at a time when its rivals were not willing to make the investment.

There was “a well-orchestrated campaign” for Openreach to be separated from BT but, while there were customer service issues which BT acknowledged it needed to address, Openreach was not responsible for all the problems people encountered.

Sir Mike also highlighted the contribution of staff at Adastral Park to the development of new ultra-fast broadband, which BT has pledged to roll out to 12 million premises by the end of 2020, and the research facility’s continuing role in developing technology offering even higher speeds for the future.